The invention relates to machines for filling containers with liquid.
Specifically, the invention has been developed for the filling of beer kegs. Such a keg has a closure unit which has one or two spring loaded valve members which act to seal the keg. The closure units are arranged so that the valve members may be opened to fill the keg, or dispense beer from the keg, with the closure unit in place in the keg. Such a keg is filled against a counter-pressure of carbon dioxide and beer is dispensed from a keg under a top pressure of carbon dioxide.
When a keg has been filled with beer, before it is disengaged from the head through which it has been filled, the pipework is cleared of beer. This is known as "saving" the beer and is the last step carried out before the filled keg is disengaged from the filling head.
Although the beer is saved, before it can be used again, it has to be resterilized and this of course is expensive.